Zhibao Li

Reaction kinetics of peracetic acid from acetic acid and hydrogen peroxide in a helical capillary microreactor was investigated and modelled via regression of the measured conversion rate of hydrogen peroxide. It was found that the activity of the proton in the sulphuric acid solution played a significant role in the synthesis as a catalyst. The activities of the proton were calculated with the ELECNRTL equation and used to obtain a kinetic model with the apparent activation energy of peracetic acid synthesis and hydrolysis of 53.63 and 54.45 kJ/mol, respectively. A new continuous process for industrial manufacture of peracetic acid solution (30 wt. %) was proposed, where the reacted solution from the microreactor is distilled to separate unreacted reactants and sulfuric acid which are recycled as feed. The feasibility of the new process was validated by economic assessment.

Alternative means for soda ash (Na₂CO₃) production from sodium sulfate (Na₂SO₄) are needed due to the intensive consumption of energy in the conventional Mirabilite-Solvay process (MSP). We demonstrate a new process to produce soda ash using sodium sulfate as a feed material. The new process relies on the antisolvent crystallization of unreacted Na₂SO₄ to separate it from soluble (NH₄)₂SO₄ in a mixed monoethanolamine (MEA) and monoethylene glycol (MEG) solution. To develop the process, the solubilities of Na₂SO₄ and (NH₄)₂SO₄ solids in aqueous mixed MEA-MEG solutions were first measured and then modeled using regressed paired-ion interactions from the electrolyte nonrandom two-liquid (E-NRTL) model. Anhydrous dense soda ash with a bulk density of up to 1146 kg/m³ was obtained when the concentrated Na₂SO₄ brines reacted with CO₂ and NH₃.